[ghaff]

Well, if you're climbing some huge mountain in the middle of nowhere you probably need to charge your Garmin as well.

Garmin absolutely has better battery life. But if you can see your way to charging the Apple Watch more frequently it seems more interesting for a combination of regular smartwatch use and day activities. And, if you are climbing huge mountains in the middle of nowhere, I assume purchasing a specialized watch if you want one is the least of your expenses. (Or something like an InReach.)

[ip26]

You may need to charge… but the Garmin uses something like ~10mAh/day? You could top off the watch for months with a single pair of AAA batteries.

[ghaff]

Just make sure you keep them warm.

It's been a while since I've done any high-altitude mountaineering. I honest don't know what people actually use these days. Certainly GPS watches didn't exist when I was climbing. Not sure if people use power-hungry watches that need to be charged these days or not.